Radiocarbon to Calendar Date Conversion: Calendrical Bandwidths as a Function of Radiocarbon Precision

Abstract

Accurate high-precision 14C dating (i.e., +/- 20 yr precision or less on the 14C date) provides the narrowest calendrical band width and, hence, the best age range determination possible. However, because of the structure in the 14C calibration curve, the calendar age range for a given 14C precision is not constant throughout the calibration range. In this study, we quantify the calendar band widths for a range of 14C previsions throughout the calibration range. We show that an estimate of the likely calendar band width in years can be obtained from the expression: Band width (yr) = 2.12 x 14C precision (1 sigma) + 54.6. We also show that calendar band widths are widest around 4000 BP at the start of the Bronze Age, and become narrow through the later Bronze Age and Iron Age and back into the Neolithic.